Correlation between changes of medial rectus muscle section and enophthalmos in patients with medial orbital wall fracture.
BACKGROUND
Enophthalmos is the most distressing and common complication of the blow-out fracture. In spite of well-established indications for early operative repair of orbital fracture, 7-10% of patients treated non-operatively develop enophthalmos. There have been reports on the correlation between changes of orbital bone and enophthalmos; however, there is no report on muscle changes in computed tomography (CT) in medial blow-out fracture. The present authors have documented the correlation between change of medial rectus muscle and enophthalmos using CT scan in medial blow-out fracture patients.


METHODS
In this study (from January 2001 to December 2006) of 340 patients diagnosed with medial blow-out fracture, 24 patients were treated non-operatively. Nine patients (Group 1) have over 2-mm enophthalmos and 15 patients (Group 2) have enophthalmos less than 2mm. The height-to-width (H-W) ratios of medial rectus muscle were measured in coronal views, and the size of defects were measured in coronal and axial views in CT. Hertel's exophthalmometry was measured on both eyes for all patients.


RESULTS
The H-W ratios measured in the affected orbits were statistically significant between the two groups (p<0.0001). However, the size of defect is not related with enophthalmos in two groups statistically (P=0.421).


CONCLUSIONS
These results mean that the H-W ratio of medial rectus muscle in coronal views of CT is a useful parameter to predict enophthalmos, and whether H-W ratios of medial rectus muscle over 0.7 need surgical correction.
Kim
Yong Kyu
YK
Department of Plastic and Reconstructive Surgery and Physiologic Lab, College of Medicine, Inje University, Ilsan Paik Hospital, Goyang, Kyuggi, Republic of Korea. psinbrain@hotmail.com
Park
Chang Sik
CS
Kim
Hyoung Kyu
HK
Lew
Dae Hyun
DH
Tark
Kwan Chul
KC
D000293:Adolescent; D000328:Adult; D002648:Child; D015331:Cohort Studies; D015841:Enophthalmos / Q000000981:diagnostic imaging / Q000209:etiology* / Q000628:therapy; D005260:Female; D005500:Follow-Up Studies; D005592:Fracture Fixation / Q000379:methods; D017102:Fracture Healing / Q000502:physiology; D006801:Humans; D015601:Injury Severity Score; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods; D009801:Oculomotor Muscles / Q000503:physiopathology*; D009917:Orbital Fractures / Q000150:complications* / Q000000981:diagnostic imaging / Q000601:surgery / Q000628:therapy*; D011336:Probability; D012189:Retrospective Studies; D018570:Risk Assessment; D014057:Tomography, X-Ray Computed / Q000379:methods; D016896:Treatment Outcome; D055815:Young Adult